<?php
//$n表示区间的最小值，$m表示区间的最大值
$n = 100;
$m = 1300;
$sum = [];
for ($i=$n;$i<=$m;$i++){
        $sum[] = $i+1;
}
//foreach($sum as $v){
//    $sum=$v+1;
//}
echo substr_count(implode($sum,','),1);
//return $sum;

//$res = range(100,1300);
//$data = implode($res,',');
//echo substr_count($data,'1');

?>